The present invention relates to a metering ball-valve to dispense a unit volume and, more particularly, to such a ball-valve when received within a resilient split housing.
Metering ball-valves are known in which by rotation of the ball-valve in a housing, a blind bore in the ball may be moved from a position in which it receives material to be dispensed in another position in which it may dispense the material received.
Previously known ball-valves suffer the disadvantage, particularly when used for dispensing granular material, that any material which may become adhered to the surface of the ball can prevent rotation of the ball and thus a jamming condition can arise. Such conditions may occur particularly in conditions when materials to be dispensed include granular materials which can become sticky or fused to the ball and become wet as in humid conditions.
To at least partially overcome these disadvantages of previously known devices, the present invention provides a dispensing ball-valve in which the housing comprises two complementary half members resiliently biased together and adapted for separation from each other.
An object of the present invention is to provide an improved dispensing ball-valve.
Another object of the present invention is to provide a ball-valve in which the housing within which the ball is received comprises two half members resiliently biased together and adapted to separate from each other against such bias.
In one aspect, the present invention provides a ball-valve, comprising:
a housing having an inner spherical cavity with a first port opening into the cavity from a first side of the housing and a second port opening into the cavity from a second opposite side of the housing,
a ball concentrically received in the housing in the cavity for rotation about a first axis through the center of the spherical cavity,
the ball having spherical outer surfaces for sealed engagement within the cavity,
the ball having a blind-bore of a known volume;
the ball adapted to be rotated about the first axis between a first position, in which the blind-bore communicates with the first port, and a second position in which the blind-bore communicates with the second port;
the sealing engagement between the spherical outer surfaces of the ball and the cavity being maintained during rotation of said ball between the first and second positions whereby rotation of the ball between the first and second positions is adapted to move a predetermined volume from communication with the first port to communication with the second port,
the housing comprising two complementary half members, a first half member carrying the first port and a second first half member carrying the second port, with each half member carrying about one half of the cavity,
the first and second half members coupled together to form the cavity therebetween with a first generally equatorial mating surface on the first half member adapted to removably scalably engage a second generally equatorial mating surface of the second half member,
a biasing mechanism resiliently biasing the first and second half members together to urge the first generally equatorial mating surface into sealed engagement with the second generally equatorial mating surface,
wherein the first and second half members are adapted to separate from each other over their equatorial mating surface against the bias of the biasing mechanism.